Unusual Clinical Features of Toscana Virus Central Nervous System Infections in Italy

Objective: This study was aimed at reviewing a case series of 35 patients with neuroinvasive Toscana Virus (TOSV) infections, to evaluate clinical findings and outcomes. Methods: A retrospective analysis was conducted in two secondary referral facilities in Italy. Patients with confirmed TOSV infection were included. Biochemical and serological analyses of blood and cerebrospinal fluid (CSF), as well as radiological imaging, were conducted. Results: A total of 35 cases of neuroinvasive TOSV infection were analyzed (in 28 men and 7 women): 32 (in 25 men and 7 women) with a diagnosis of meningitis with clear CSF and 3 (in only men) with a diagnosis of encephalitis. No fatalities or permanent outcomes were observed in the meningitis cases. Three patients with encephalitis were admitted to intensive care because of psychomotor agitation that lasted at least 12 hours and tended to worsen. All but one patient with encephalitis fully recovered with no neurological sequelae after a mean of 6.3 days of acute care. A 73-year-old man developed a chronic psycho-organic syndrome. Conclusions: Most TOSV infections are asymptomatic, mild, or undiagnosed; however, cases of severe disease are increasing, because of TOSV’s specific affinity for the nervous system, both central and peripheral.